There is known an image forming apparatus having a fixing device and a sheet ejection opening for ejecting paper (recording sheet), which are provided in an upper part of a main body casing, and air heated by the fixing device is discharged through the sheet ejection opening (see, for example, JP2000-293075 A). More specifically, the fixing device has a heating roller and a pressing roller arranged one behind another in the front-rear direction, and a slanted wall extending diagonally upward and rearward to the sheet ejection opening is provided above the heating roller and the pressing roller.
With this configuration, air heated by the fixing device flows along the slanted wall and is discharged through the sheet ejection opening. Further, a downwardly extending projection is provided on the slanted wall at a position rearward of the center of the pressing roller.
However, according to this image forming apparatus, when paper is heated by the heating roller, moisture contained in the paper vaporizes and flows, together with the heated air, along the slanted wall. Therefore, if the slanted wall is cool, water vapor may be cooled by the slanted wall and dew condensation may occur. In particular, the slanted wall is likely to be cooled by the outside air at a region closer to the sheet ejection opening, with the result that dew condensation is more likely to occur in this region of the slanted wall.
Once dew condensation occurs and dew droplets are condensed on the slanted wall at the region closer to the sheet ejection opening, the dew droplets run down along the slanted wall in a diagonally downward and frontward direction and then they are stopped by the projection, so that, at the projection of the slanted wall, the dew droplets drop and may disadvantageously adhere to the paper being conveyed toward the sheet ejection opening. If the dew droplets drop on the paper, an image formed on the paper may be stained with the dew droplets and the image quality of the printed paper may be degraded.
In view of the above, it would be desirable to provide an image forming apparatus which can restrain dew droplets caused by dew condensation from adhering to paper (recording sheet) so as to suppress degradation of the printed image.